TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

234 Chapter5
TurboIMAGE/XL Library Procedures
DBXBEGIN
DBXBEGIN
INTRINSIC NUMBER 420
Designates the beginning of a sequence of TurboIMAGE/XL procedure calls that are to be
regarded as a dynamic transaction of a single database or dynamic transaction spanning
multiple databases (DMDBX) for the purposes of logging and dynamic roll-back recovery. The
text parameter can be used to log user information to the log file. DBXBEGIN is used in
conjunction with DBXEND to begin and end a dynamic transaction.
Syntax
DBXBEGIN,{ base
baseidlist
}, te0xt,mode,status,textlen
Parameters
base is the name of the array used as the base parameter when opening the
database. The first element of the array must contain the base ID returned
by DBOPEN. (Refer to DBOPEN for more information about the base ID.)
baseidlist is the name of the integer array containing the base IDs of the databases
which are involved in a DMDBX. Use
baseidlist when calling DBXBEGIN
mode 3 (DMDBX). The layout of this array is shown here (each element is a
halfword or two bytes):
Element Contents
1-2 Application program must set these two halfwords to
binary 0s before calling DBXBEGIN. After returning to the
calling program, these two halfwords contain the
transaction ID. Use this same
baseidlist with the
corresponding DBXEND or DBXUNDO intrinsics.
3 Number of base IDs involved in the DMDBX. This must be a
number between 1 and 15 inclusive.
4-
n Base IDs of the databases involved in the DMDBX. Each
base ID occupies one half-word or 2 bytes and it is the first
halfword of the
base parameter used to call
TurboIMAGE/XL intrinsics.
text is the name of an array up to 256 halfwords long that contains user ASCII
or binary data to be written to the log file as part of the DBXBEGIN log
record. The text argument is used to assign each particular transaction a
distinct name. (Refer to "Discussion" below for more information.)
mode is an integer indicating the transaction type:
Mode 1: Indicates a dynamic transaction which spans only one
database.